I. Field of the Invention
The present invention relates to a steering wheel tilt device having a function of tilting up a steering wheel to allow a driver to get on or off easily.
II. Description of the Related Art
Up to now, a steering wheel of a vehicle is fixed, and a lower portion of the steering wheel interferes with a leg of a driver when the driver gets on or off. Thus, the driver finds it difficult to get on or off. In order to solve this problem, therefore, there have been adopted a method of tilting up an entire steering including a steering shaft (see JP 2000-272524 A) and a method of tilting up only the steering wheel.
However, according to the method of moving the entire steering including the steering shaft, a corresponding mechanism needs to be provided already in the initial phase of manufacture. Thus, this method is not applicable to vehicles unequipped with such a mechanism, for example, sports utility vehicles and the like.
According to the current method of tilting up only the steering wheel, two components, which are provided on a steering wheel side and a steering boss side respectively as a basic structure, are coupled together by a spring-loaded pawl or the like. These components include a hinge shape as a combination of a projecting portion and a depressed portion. A certain difference in dimension is set between the projecting portion, which can be inserted into the depressed portion, and the depressed portion to ensure smoothness in mounting/removing operations. Thus, the occurrence of backlash results from a radial load in steering the steering wheel when the two components are coupled together.
In addition, it is also possible to adopt a construction in which a steering wheel is removably mounted (see JP 2002-178933 A). This construction also serves to eliminate interference of the steering wheel when a driver gets on or off. However, after having removed the steering wheel and got off, the driver must bother to carry the steering wheel about or mount it again.
In the foregoing construction in which the steering wheel is removably mounted, it is also conceivable to simply provide a socket and a plug with a rotational shaft for making a hinge movement to tilt up the steering wheel. In this construction, however, when a force for holding a ball is increased to suppress backlash, a large force is required to disconnect the steering wheel, which makes opening/closing movements thereof difficult. When the force for holding the ball is reduced to facilitate the opening/closing movements, backlash is caused.